Elevator safety device



l July 23, 1935. w. J. MARTIN EIl-IEVATOR SFETI DEVICE Filed Aug. ll, 1951 `4) Sheets-Sheet l July 23, 1935.

W, J. MARTIN ELEVATOR SAFETY DEVICE Filed Aug. ll, 1931 4 Sheets-'Sheet 2 Juy 23, 1935.

w. J. MARTgN ELEVATOR SAFETY DEVICE Filed Aug. ll, 1931 4 Sheets-Sheet July 23, 1935. W MARTlN 2,908,721l

' ELEVATOR SAFETY DEVICE Filled Allg. 1l, 1931 4 Sheets-Sheet 4 lNvENTOR ATTORNEYS Patented July 23, 1935 UNITED STATES PATENT OFFICE Application August 11,

12 Claims.

This invention relates to a device associated with an elevator which is moved vertically in an elevator well having doors at one or more doors,- the safety feature of the device being that the 6 elevator cannot be moved unless every one of the doors is closed. In particular, the invention relates to an elevator system in which the doors at each floor are of the dual, interconnected type and move toward each other to close their cornpanion doorway.

One of the objects of the invention is to provide a reliable and inexpensive device which enables a single electric switch, located in the pent house of the building, to be actuated by any one of the various doors at the different floors.

Another object of the invention is to lock each companion pair of dual doors to each other when in their closed position so that the position of both determines whether or not electric current is to be allowed to flow to the elevator motor.

A further object of the invention is, in a case of emergency, to allow ingress into the elevator well even though every door be locked on the inside.

Numerous other objects of the invention and practical solutions thereof are disclosed in detail in the herein patent specification wherein, in the accompanying drawings:-

Figure 1 is a diminutive, fragmentary, vertical section through an elevator well and associated parts showing the same equipped with my new safety device.

Figure 2 is a similar vertical section but taken at right angles to Fig. 1 on line 2-2, Fig. 1.

Figure 3 is a fragmentary, vertical section through an elevator well and associated parts showing a modified form of the invention as applied to single, sliding doors and showing such a door in its open position.

Figure 4 is an enlarged, fragmentary, horizontal section of the master switch taken on line 4-4, Fig. 3.

Figures 5 and 6 are enlarged, vertical sections through said master switch taken on correspondingly numbered lines of Figs. 4 and 3.

Figure 7 is an enlarged, vertical, longitudinal section through said master switch taken on line 1-1, Fig. 6.

Figure 8 is a fragmentary, enlarged front elevation of the dual door locking apparatus shown in Figs. 1 and 2.

Figure 9 is a horizontal section thereof taken on line 9 9, Fig. 8.

Figure 10 is a fragmentary, enlarged horizontal 1931. Serial No. 556,372

section through a portion of the dual door locking apparatus taken on line Iii-I0, Fig. 8.

Figure 11 is a fragmentary, enlarged, vertical section through said door locking apparatus taken on line lI--I i, Fig. 8.

Fig. 12 is a diminuative, schematic vertical section of elevator well showing the complete assembly of my invention with the rest of the elevator apparatus.

In the following description, similar characters of reference indicate like parts in the several figures of the drawings.

My invention may be embodied in various forms and in elevator safety devices of different constructions, and the present applications are therefore to be regarded merely as a small number of the possible organizations which come within the scope of my invention and satisfactorily carry out the function of same in practice. As here shown, the same is constructed as follows:

The numeral represents one of the four vertical walls of an elevator shaft or well 2| in which is arranged a conventional, vertically-movable freight elevator I3 supported upon an elevator cable il. The latter is vertically actuated from a conventional cable drum i5 driven through worm or other gearing IB by an electric elevator motor I1. This electric motor is in series with a pair of switches, the one, I8, of which is manually actuated by the elevator operator and is located in the elevator, while the other switch is automatic in its operation and is arranged at the outer end of the drum 35, as hereinafter to be described. The electric power, which passes in series through said manual and said automatic switch and thence to the elevator motor I1, is derived from a conventional source of power i9.

The elevator well 2| is provided with a number of doorways 22 at the different floor levels 23. Each of said doorways is adapted to be either closed or opened by a pair of dual doors consisting of an upper or primary door 24 and a lower or secondary door 25. Each companion pair of dual doors is arranged in the usual and well known manner (not necessary to be here shown) whereby the force imparted to either open or close any certain primary door 24 is in the same measure transmitted to, and in a corresponding direction with, its companion secondary door 25. This relative direction of movement of said doors is indicated by arrows in the several views.

Arranged at the upper end of the elevator well pression spring 44.

2| is the usual roof 26 of the building upon which is located a conventionalized pent house 21. Located within said pent house and suitably secured to a base plate 28 are a pair of uprights or standards 30 and 3| in which is rigidly mounted a horizontal screw 32 the one end of which is, however, unthreaded. This screw is prevented from rotating by reason of suitable set screws 33 and 34 threaded through the standards 30 and 3| and bearing with their inner ends against the periphery of said screw. Longitudinally and slidably mounted upon said screw 32 is a wide faced drum 35 the front end of which is coaxially provided with an internal screw thread which engages with the external screw thread of the screw 32. The rear end of said drum is reamed out at 36 so as to be a running t on the smooth or rear end of said screw 32. By this construction the whole drum 35 is caused to move longitudinally forward or backward as it is rotated in the one or other direction.

Secured by at headed machine screws 31 to the front vertical end face of the drum 35 is an electrical insulating disk 38 which is constructed of iiber, synthetic resin or other similar insulating material. This insulating disk 38 is segmentally cut out to receive with a flush fit, a metallic segment 40 which is secured to said insulating disk by a number of shallow machine screws 4|. Longitudinally and slidably arranged in the front drum standard 30 are a horizontally disposed pair of electrical plungers or switch contacts 42, the outer ends of which are connected to electrical lead wires 43 which convey the electrical current in series through the various electric apparatus (motor, elevator switch, relays, etc.) whereby the operator is enabled to cause the elevator to move up or down in the elevator well 2|. The only important matter to be here noted is that the switch contacts 42 and metallic segment 40 and associated parts constitute a master switch which when closed permits the elevator motor to receive electrical energy but which, when open, absolutely prevents said elevator motor from receiving electrical energy irrespective of the position of the other switches, relays, etc.

These switch contacts are suitably insulated from the front standard 3U, and each is resiliently urged rearwardly by a companion com- The longitudinal, rearward movement of each of said switch contacts 42 is, however, definitely restricted by means of a stop collar 45 which is preferably formed integral with its companion switch contacts and which, in its rearmost position, bears against the bottom of the coaxial, longitudinal, horizontal hole that receives its companion compression spring 44. The consequence of this construction is that, as the drum 35 is rotated, the switch contacts 42 are caused to rst break electrical contact with the metallic segment 40, the springs 44 in the meantime causing said contacts to maintain an electrical contact and the stop collars 45 not yet having struck bottom during the thus far small recession longitudinally of the entire drum. Any electrical arcing which does occur when the current is broken is entirely confined to the one end of the segment 40, and this end is remote from the area touched by the switch contacts 42 when the doors are all fully closed. Hence, what arcing does occur cannot cause a pitting of the actual points of effective electrical contact. At this time, however, the rear ends of said switch contacts 42 are still in contact with the front end of said drum 35 so that if a considerable portion of water or dirty oil is present a certain amount of electrical energy might still flow through the master switch. To eliminate any possibility of such an electrical leakage, the ratio ,of' drum diameter to door movement is such that after the metallic segment 40 moves past the end of one of the switch contacts 42, the drum continues to rotate until it has moved longitudinally sufhciently rearward so that there is an actual air gap between said switch contacts 42 and the front end of the drum 35, thereby positively ensuring that, when the doors 24, 25 are open, absolutely no current can be fed to the elevator motor.

A control cable 46 is secured by a cleat 41 to the periphery of the drum 35 and is given a few turns around said drum at opposite sides of said cleat. The outer end of said control cable passes downwardly from said drum and is secured to a weight 48 which at all times tends to rotate said drum so as to move the same longitudinally forward and thereby to close the electrical circuit through the switch contacts 42. Secured by bolts 50 to the secondary door 25 is an arm 5| which is bored vertically to receive the rear, downwardly hanging end of the cable 46, said rear end continuing down around a suitable take up pulley 52 (which is pivoted to the stationary footing 53 of the elevator well 2|) and thence passes up and is secured to the lower end of aforesaid weight 48, thereby completing the circuit of said control cable.

Secured in the usual and well known manner to said control cable 46 by means of clamping screws 54 (see Figs. 8, 11 and 2) is a cable clip 55 the upper square end of which is adapted to bear against the lower flat face of the arm 5| of the secondary door 25. Thus, when said secondary door is lowered (opened), the clip 55 is pushed downwardly thereby rotating the drum 35 and opening the circuit through the master switch, i. e., through the switch contacts 42 and thus also opening the circuit through the motor which drives the elevator.

It is to be recalled that the primary and secondary doors 24 and 25 move in synchronism with respect to each other, being interconnected so that when the upper door 24 raises, the lower door 25 is depressed. Ordinarily the operator applies manual force to the upper or primary door 24 while the lower door is caused to open by the force derived from the movement of said primary door. Means are provided for locking the primary or upper door to the secondary or lower door so that neither door can be moved until a suitable trip lever 56 is actuated. The arrangement by which these two doors are locked together is constituted as follows:

Secured to the upper face of the arm 5| of the secondary door 25 is a cylindrical, vertical guide 51. Vertically slidable within the bore of said guide 51 is a locking plunger 58 which is limited in its upward movement relatively to said arm 5| by the provision of a stop collar 60 which is screwed upon its lower end. The upper end of said plunger 58 is provided with a conical head 6| which tapers upwardly and inwardly. The plunger is bored longitudinally and coaxially to give a loose sliding fit on the control cable 46, while the upper part of the clip 55 is coaxially and downwardly recessed to very loosely receive the stop collar 60 of said plunger, the depth of said recess being such that, with the parts in the locked position of Figs. 8-11, there is a sizeable clearance space between the top of the stop collar 60 and the bottom of the guide 51. It will be noted that, in this position, the top of said clip 55 is in contact with the bottom face of the arm 5|.

The primary or upper door 24 is provided with a laterally or outwardly projecting arm 62 secured to said door by bolts 63 or otherwise. Said arm 62 is vertically drilled to receive the locking plunger 58, the drilled hole having suicient diameter to allow the conical head 6| of said plunger to pass easily therethrough. Fulcrumed at 64 upon the primary door 24 is the aforementioned trip lever 56, the same being vertically guided within the vertical slot 65 of a guide bracket 66 and a suitable handle 61 being provided to facilitate its manipulation by the operator of the elevator. The outer end of said trip lever terminates in a depressing tongue 68 which is adapted to bear downwardly against the upper inner end of a releasing lever 10. The latter is horizontally pivoted at 1| to a base block 12 which is suitably secured by welding or otherwise to the upper face of the arm 62. This releasing lever 10 at its outer end rises up above its supporting block 12 and then extends outwardly in an approximately horizontal direction to form a lifting tongue 13.

A base block 12|] is secured to the upper face of said arm 62, similarly to the block 12. Pivoted at 1| and 1|0 to and situated between said base blocks 12, is a pair of locking dogs 14 which are provided with lifting pins 15 and 150. These pins project out horizontally and laterally from one side of their companion dogs and rest upon the upper at edge of the hereinbefore described lifting tongue 13.

Operation The primary and secondary doors 24 and 25 are shown in the various gures in their closed position. To open the same the operator of the elevator lifts the handle 61 of the trip lever 56 and partially rotates the same in a vertical plane about its fulcrum 64. This moves downwardly the depressing tongue 68 of said trip lever and this movement in turn is imparted in a downward direction to the inner end of the releasing lever 10 which partially rotates about its pivot 1| and causes its outer end or lifting tongue 13 to be raised. This movement in turn is imparted in an upward direction to the lifting pins 15, which tends to cause the locking dogs 14 to move upwardly and outwardly away from each other. It is to permit this movement that a certain clearance space is provided between the top of the stop collar 60 (of the locking plunger 58) and the bottom of the vertical guide 51. Further movement of said locking dogs causes their noses to be entirely disengaged from the lower annular shoulder of the conical head 6| of said locking plunger 58. The upper and lower doors 24, 25 are now unlocked from each other and the operator is able to lift the upper or primary door 24 and this movement in the usual and well known manner is imparted to the lower or secondary door 25 to depress the same.

This downward movement of the lower or secondary door 25 causes the lower face of its arm 5| to bear down upon the upper face of the cable clip 55 and the latter, being adjustably secured to the control cable 46, causes the drum 35 in pent house 21 to be rotated and retracted. The rst part of this movement causes the metallic segment 40 to be rotated out of register with the switch contacts 42 thereby breaking the electrical circuit through the electrical lead wires 43 and through the elevator motor. This action also connes any electrical arcing action to the extreme edge of said segment 40. Further rotation and retraction of said drum causes its outer face to be moved entirely out of Contact with said switch contacts 42 (see Fig. 3) by reason of the stop collars 45, thereby absolutely cutting oi any possibility of current flow even though the drum face be dripping with oil or water.

The elevator doors are now open and the elevator is either loaded or unloaded as the case may be. While this operation is going on all the other doors are prevented from being opened by unauthorized persons by reason of the fact that all of said doors are locked together by means of the dogs 14 and these can only be unlocked by a manipulation of the trip lever 56 which is located interior-ly of the elevator well.

When the loading or unloading of the elevator has been completed at any certain floor level, the operator merely closes the doors 24, 25 at that level. This movement automatically permits the weight 48 to wind the drum 35 upon the screw 32 so as to rotate the same and move it longitudinally back to the position shown in Figs. l, 2, 4J?, thus permitting the ilow of current through the switch contacts 42 of the master switch so that the elevator operator is free to supply current to the elevator motor by a manipulation of his elevator cage rheostat or other electrical control apparatus.

If the operator should faint, or if for any other reasons it is necessary to gain access to the elevator well 2| from the outside, with all the doors locked from the inside, special emergency or auxiliary means of unlocking at least one of the elevator doors is required. In the present invention this auxiliary means consists of a special key 16 (Figs. 8 and 9) which may be inserted from the outside of the elevator well 2| through a key hole 11 so that its shank lies within a hollow groove 18 of a thrust block 80, the latter being suitably secured to one of the primary doors 24 by wood screws 8| or otherwise. By turning this key 16, the trip lever 56 is caused to be moved in precisely the same manner as when the regular elevator operator lifts the handle 61 of said trip lever.

In Fig. 3 is shown a slight modification of the invention which is in all general respects equivalent to that heretofore described except that here a single elevator door 250 is employed instead of the dual doors 24, 25.

I claim:

1. An elevator safety device comprising an elevator; an elevator well having a pair of oppositely opening doors; an elevator motor; a control cable adapted to be moved by one of said doors; means operatively connected with said cable and adapted to control the actuation of said elevator motor; and means actuated by said cable for locking the other door to said rst named door.

2. An elevator safety device comprising an elevator; an elevator well having a pair of oppositely opening doors; an elevator motor; a control cable adapted to be moved by one of said doors; means operatively connected with said cable and adapted to control the actuation of said elevator motor; means actuated by said cable for locking said doors together when said doors are in their closed position; and manually operated means for unlocking said doors from each other.

3. An elevator safety device comprising an elevator; an elevator well having a doorway and a primary and a secondary door which move toward each other to close said doorway; an elevator motor; a control cable adapted to be moved by the opening of said secondary door; means operatively connected with said cable and adapted to control the actuation of said control motor; a dog pivotally mounted on said primary door; and a locking sleeve connected with said secondary door and adapted to be actuated by said cable to engage with said dog when the doors are in their closed position.

4. An elevator safety device comprising an elevator; an elevator well having a doorway and a primary and a secondary door which move toward each other to close said doorway; an elevator motor; a control cable adapted to be moved by the opening of said secondary door; means operatively connected with said cable and adapted to control the actuation of said control motor; a dog pivotally mounted on said primary door; a locking sleeve connected with said secondary door and adapted to be actuated by said cable to engage with said dog when the doors are in their closed position; and means for uncoupling said dog from said sleeve when the doors are to be opened.

5. An elevator safety device comprising an elevator; an elevator well having a pair of oppositely opening doors; an elevator motor; a control cable adapted to be moved by one of said doors; means operatively connected with said cable and adapted to control the actuation of said elevator motor; means actuated by said cable for locking said doors together when said doors are in their closed position; normal means for unlocking said doors from each other; and auxiliary means for also unlocking said doors from each other in an emergency.

6. An elevator safety device comprising an elevator; an elevator well having a pair of oppositely opening doors; an elevator motor; a control cable adapted to be moved by one of said doors; means operatively connected with said cable and adapted to control the actuation of said elevator motor; means actuated by said cable for locking said doors together; means located on the inside of one of said doors for unlocking said doors from each other; and auxiliary means located exteriorly of the elevator well for also unlocking said doors from each other in an emergency.

'7. An elevator safety device comprising an elevator; an elevator well having a doorway and a primary and a secondary door which move toward each other to close said doorway; an elevator motor; a control cable adapted to be moved by the opening of said secondary door; means operatively connected with said cable and adapted to control the actuation of said control motor; a locking sleeve connected with said secondary door; means actuated by said cable for locking said sleeve to said primary door; and a lever fulcrumed on said primary door and adapted to unlock the same from the secondary door.

8. An elevator safety device comprising an elevator; an elevator well having a doorway and a primary and a secondary door which move toward each other to close said doorway; an elevator motor; a control cable adapted to be moved by the opening of said secondary door; means operatively connected with said cable and adapted to control the actuation of said control motor; a locking sleeve connected with said secondary door; means actuated by said cable for locking said sleeve to said primary door; a lever fulcrumed on said primary door and adapted to unlock said primary door from said sleeve; means inside the elevator well for actuating said lever; and emergency means for actuating said lever exteriorly of said elevator well.

9. An elevator safety device comprising an elevator; an elevator well having a doorway and a primary and a secondary door which move toward each other to close said doorway; an elevator motor; a control cable adapted to be moved by the opening of said secondary door; means operatively connected with said cable and adapted to control the actuation of said control motor; a dog pivotally mounted on said primary door; a locking sleeve actuated by said cable and longitudlnally movable a limited distance with respect to said secondary door and adapted to engage with said dog when the doors are in their closed position and means for unlocking said dog from said sleeve.

10. An elevator safety device comprising an elevator; an elevator well having a doorway and a primary and a secondary door which move toward each other to close said doorway; an elevator motor; a control cable adapted to be moved by the opening of said secondary door; means operatively connected with said cable and adapted to control the actuation of said control motor; a locking sleeve actuated by said cable and connected with said secondary door; a pair of dogs mounted on said primary door at opposite sides of said sleeve and adapted to engage therewith when the doors are in their closed position; and means for simultaneously dlsengaging both of said dogs from said sleeve.

11. An elevator safety device comprising an elevator; an elevator well having a. doorway and a primary and secondary door which move toward each other to close said doorway; an elevator motor; a control cable; means operatively connected with said cable and adapted to control said motor; a c ip on said cable and adapted to be actuated by an opening movement of said secondary door; a sleeve connected with said secondary door and adapted to be actuated by said clip; a dog connected with said primary door and adapted to engage with said sleeve when said doors are in their closed position; and means for disengaging said dog.

12. An elevator safety device comprising an elevator; an elevator well having a doorway and a primary and secondary door which move toward each other to close slid doorway; an elevator motor; a control cable; means operatively connected with said cable and adapted to control said motor; a clip on said cable and adapted to he actuated by an opening movement of said secondary door; a sleeve having a limited movement re'atively to said secondary door and adapted to be actuated by said clip; a dog connected with said primary door and adapted to engage with said sleeve when said doors are in their closed position; and means for disengaging said dog.

WILLIAM J. MARTIN. 

